Going against all the good advice we were given as children, researchers have suggested that pulling faces - or so-called "facial yoga" - could make a person look three years younger. But is this claim too good to be true?
Facial yoga generally involves pulling a series of facial expressions to work different areas of the face, and using the hands to smoothe and massage the skin.
To investigate whether facial yoga can make a person appear younger, researchers taught 27 predominantly white women aged between 40 and 65-years-old how to perform a range of exercises, including smiling and sucking in the cheeks.
The group was asked to carry out the movements for 30 minutes every day for eight weeks. They were then asked to complete the exercises every other day for a further 20 weeks.
The participants had their photos taken at the beginning and end of the study. Doctors were then asked to guess which images were taken before the research, as well as the age of the person in the photo.
The doctors commented that the women's cheeks appeared fuller and three years younger on average at the end of the study. This may be due to the fact that facial yoga builds the cheek muscles and creates a fuller appearance, reasoned the authors of the study published in the journal JAMA Dermatology.
However, the researchers admitted that with such a small cohort of participants, their findings need to be backed up by a larger study. Further research is also needed to pinpoint whether men and people of different ages and ethnicities would experience the same results.
Lead author Dr Murad Alam, vice chair and professor of dermatology at Northwestern University Feinberg School of Medicine, also warned in an interview with Live Science that repetitive movements can also worsen the sign of fine lines and wrinkles.
Dr Dan Marsh, a member of the British Association of Aesthetic Plastic Surgeons council who specialises in facial rejuvenation, was sceptical of anti-ageing properties of facial yoga. He told IBTimes UK: "Face yoga will improve the muscle tone under the skin, however the ageing process is due to soft tissue elasticity and the downward movement of facial soft tissues which are in fact external to the muscles.
"Therefore by tightening the muscles you wouldn't actually be lifting the ligaments, only tightening the muscles so wouldn't actually be noticeable to the external eye."
Harley Street skincare expert Dr David Jack agreed, and told IBTimes UK: "Like most fads in skin treatments, there is absolutely zero substantial evidence that 'facial yoga' has any beneficial effects from a medical or dermatological point of view."
And considering that the participants invested as much as 30 minutes a day in the process for relatively minimal and unproven returns, those concerned about ageing might be advised to instead protect their skin.
According to the American Academy of Dermatology, applying a basic SPF 30 sunscreen every day; avoiding the sun; avoiding repetitive facial expressions such as frowning; eating a healthy, well-balanced diet low in sugars and other refined carbohydrates and exercising regularly all prevented ageing. Stopping smoking and drinking was also advised while washing the face twice a day - but not too vigorously - and applying moisturiser was recommended.